<template>
  <div class="course">
    <Header></Header>
    <div class="main">
      <!-- 筛选条件 -->
      <div class="condition">

        <ul class="cate-list">
          <li class="title">课程分类:</li>
          <li :class="{this: category===0}" @click="category=0">全部</li>
          <li v-for="(value, index) in category_list" :key="value.id" :class="{this:category===value.id}" @click="category=value.id">{{value.name}}</li>
        </ul>
        <div class="ordering">
          <ul>
            <li class="title">筛&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;选: </li>
            <li class="default" @click="ChangeOrderType('id')" :class="ChangeOrderClass('id')">默认</li>
            <li class="hot" @click="ChangeOrderType('students')" :class="ChangeOrderClass('students')">人气</li>
            <li class="price" @click="ChangeOrderType('price')" :class="ChangeOrderClass('price')">价格</li>
          </ul>
          <p class="condition-result">共21个课程</p>
        </div>

      </div>
      <!-- 课程列表 -->
      <div class="course-list">
        <div class="course-item" v-for="(value, index) in course_list" :key="value.id">
          <div class="course-image">
            <img :src="value.course_img" alt="">
          </div>

          <div class="course-info">
            <h3><router-link :to="`/course/detail/${value.id}/`">{{value.name}}</router-link> <span><img src="/static/image/avatar1.svg" alt="">{{value.students}}人已加入学习</span></h3>
            <p class="teather-info">{{value.teacher.name}} {{value.teacher.signature}} {{value.teacher.title}} <span>共{{value.lessons}}课时{{value.lessons === value.pub_lessons?'/更新完成':`/已更新${value.pub_lessons}`}}</span></p>
            <ul class="lesson-list">
              <li v-for="(lesson_value, lesson_index) in value.lesson_list" :key="lesson_value.id">
                <span class="lesson-title">0{{lesson_value.lesson}} | 第{{lesson_value.lesson}}节：{{lesson_value.name}}</span>
                <span class="free">{{lesson_value.free_trail?'免费':'收费'}}</span>
              </li>
            </ul>
            <div class="pay-box">
              <span class="discount-type" v-if="value.discount_name">{{value.discount_name}}</span>
              <span class="discount-price">￥{{value.active_real_price}}元</span>
              <span class="original-price" v-if="value.discount_name">原价：{{value.price}}元</span>
              <span class="buy-now">立即购买</span>
            </div>
          </div>

        </div>
      </div>
    </div>
    <el-pagination
      background
      layout="prev, pager, next, sizes"
      :page-size="filters.size"
      :page-sizes="[2, 3, 5, 10]"
      :total="total"
      @current-change="HandlerCurrentChange"
      @size-change="HandlerSizeChange">
    </el-pagination>
    <Footer></Footer>
  </div>
</template>

<script>
  import Header from "./common/Header"
  import Footer from "./common/Footer"
  export default {
    name: "Course",
    data(){
      return{
        category: 0,
        category_list: [],
        course_list: [],
        total: 0, // 每次请求获取数据的总条数。

        filters: {
          type: 'id',   // 标记选中哪个标签
          order: 'desc', // 标记当前的排序状态（三角形上高亮还是下高亮）
          page: 1,  // 默认获取第一页的数据
          size: 5,  // 每页显示5条数据
        },
      }
    },
    methods: {
      get_category() {
        this.$axios.get(
          `${this.$settings.Host}/course/category/`
        ).then(
          response => {
            console.log(response.data);
            this.category_list = response.data;
          }
        ).catch(
          error => {
            console.log(error.response.data);
          }
        )
      },
      ChangeOrderType(type){
        if (this.filters.type !== type){
          this.filters.type = type;
          this.filters.order = 'desc';
        }else
        {
          if (this.filters.order === 'asc'){
            this.filters.order = 'desc'
          }else {
            this.filters.order = 'asc'
          }
        }
        this.get_course();
      },
      ChangeOrderClass(type){
        if(this.filters.type === type && this.filters.order === 'desc'){
          return 'this asc';
        }else if (this.filters.type === type && this.filters.order === 'asc'){
          return 'this desc';
        }else {
          return '';
        }
      },
      get_course() {
        let filter = {
          page: this.filters.page,
          size: this.filters.size,
        };
        if (this.category > 0){
          filter.course_category = this.category;
        }
        if(this.filters.order === 'desc'){
          console.log(this.filters.order);
          console.log(this.filters.type);
          filter.ordering = '-' + this.filters.type;
        }else {
          console.log(this.filters.order);
          console.log(this.filters.type);
          filter.ordering = this.filters.type;
        }
        /*
        filter = {
        course_category: 1, 筛选课程
        ordering: -id, 排序字段
        }
        */
        this.$axios.get(
          `${this.$settings.Host}/course/list/`,
          {
            params: filter
          }
        ).then(
          response => {
            this.course_list = response.data.results;
            this.total = response.data.count;
          }
        ).catch(
          error => {
            console.log(error.response.data)
          }
        )
      },
      HandlerCurrentChange(page){
        this.filters.page = page;
        this.get_course();
      },
      HandlerSizeChange(size){
        this.filters.size = size;
        this.get_course();
      }
    },
    watch: {
      category(){
        this.get_course();
      },
      filters(){
        this.get_course();
      }
    },
    created() {
      this.get_category();
      this.get_course()
    },
    components:{
        Header,
        Footer,
      }
  }
</script>

<style scoped>
  .course{
    background: #f6f6f6;
  }
  .course .main{
    width: 1100px;
    margin: 35px auto 0;
  }
  .course .condition{
    margin-bottom: 35px;
    padding: 25px 30px 25px 20px;
    background: #fff;
    border-radius: 4px;
    box-shadow: 0 2px 4px 0 #f0f0f0;
  }
  .course .cate-list{
    border-bottom: 1px solid #333;
    border-bottom-color: rgba(51,51,51,.05);
    padding-bottom: 18px;
    margin-bottom: 17px;
  }
  .course .cate-list::after{
    content:"";
    display: block;
    clear: both;
  }
  .course .cate-list li{
    float: left;
    font-size: 16px;
    padding: 6px 15px;
    line-height: 16px;
    margin-left: 14px;
    position: relative;
    transition: all .3s ease;
    cursor: pointer;
    color: #4a4a4a;
    border: 1px solid transparent; /* transparent 透明 */
  }
  .course .cate-list .title{
    color: #888;
    margin-left: 0;
    letter-spacing: .36px;
    padding: 0;
    line-height: 28px;
  }
  .course .cate-list .this{
    color: #ffc210;
    border: 1px solid #ffc210!important;
    border-radius: 30px;
  }
  .course .ordering::after{
    content:"";
    display: block;
    clear: both;
  }
  .course .ordering ul{
    float: left;
  }
  .course .ordering ul::after{
    content:"";
    display: block;
    clear: both;
  }
  .course .ordering .condition-result{
    float: right;
    font-size: 14px;
    color: #9b9b9b;
    line-height: 28px;
  }
  .course .ordering ul li{
    float: left;
    padding: 6px 15px;
    line-height: 16px;
    margin-left: 1px;
    position: relative;
    transition: all .3s ease;
    cursor: pointer;
    color: #4a4a4a;
  }
  .course .ordering .title{
    font-size: 16px;
    color: #888;
    letter-spacing: .36px;
    margin-left: 0;
    padding:0;
    line-height: 28px;
  }
  .course .ordering .this{
    color: #ffc210;
  }
  .course .ordering .price{
    position: relative;
  }
  .course .ordering .this::before,
  .course .ordering .this::after{
    cursor: pointer;
    content:"";
    display: block;
    width: 0;
    height: 0;
    border: 5px solid transparent;
    position: absolute;
    right: 0;
  }
  .course .ordering .this::before{
    border-bottom: 5px solid #aaa;
    margin-bottom: 2px;
    top: 2px;
  }
  .course .ordering .this::after{
    border-top: 5px solid #aaa;
    bottom: 2px;
  }
  .course .ordering .desc::after{
    border-top: 5px solid #f5a623;
  }
  .course .ordering .asc::before {
    border-bottom: 5px solid #f5a623;
  }
  .course .course-item:hover{
    box-shadow: 4px 6px 16px rgba(0,0,0,.5);
  }
  .course .course-item{
    width: 1050px;
    background: #fff;
    padding: 20px 30px 20px 20px;
    margin-bottom: 35px;
    border-radius: 2px;
    cursor: pointer;
    box-shadow: 2px 3px 16px rgba(0,0,0,.1);
    /* css3.0 过渡动画 hover 事件操作 */
    transition: all .2s ease;
  }
  .course .course-item::after{
    content:"";
    display: block;
    clear: both;
  }
  /* 顶级元素 父级元素  当前元素{} */
  .course .course-item .course-image{
    float: left;
    width: 423px;
    height: 210px;
    margin-right: 30px;
  }
  .course .course-item .course-image img{
    width: 100%;
  }
  .course .course-item .course-info{
    float: left;
    width: 596px;
  }
  .course-item .course-info h3 {
    font-size: 26px;
    color: #333;
    font-weight: normal;
    margin-bottom: 8px;
  }
  .course-item .course-info h3 span{
    font-size: 14px;
    color: #9b9b9b;
    float: right;
    margin-top: 14px;
  }
  .course-item .course-info h3 span img{
      width: 11px;
      height: auto;
      margin-right: 7px;
  }
  .course-item .course-info .teather-info{
      font-size: 14px;
      color: #9b9b9b;
      margin-bottom: 14px;
      padding-bottom: 14px;
      border-bottom: 1px solid #333;
      border-bottom-color: rgba(51,51,51,.05);
  }
  .course-item .course-info .teather-info span{
      float: right;
  }
  .course-item .lesson-list::after{
      content:"";
      display: block;
      clear: both;
  }
  .course-item .lesson-list li {
    float: left;
    width: 44%;
    font-size: 14px;
    color: #666;
    padding-left: 22px;
    /* background: url("路径") 是否平铺 x轴位置 y轴位置 */
    /*background: url("/static/image/play-icon-gray.svg") no-repeat left 4px;*/
    margin-bottom: 15px;
  }
  .course-item .lesson-list li .lesson-title{
      /* 以下3句，文本内容过多，会自动隐藏，并显示省略符号 */
      text-overflow: ellipsis;
      overflow: hidden;
      white-space: nowrap;
      display:inline-block;
      max-width: 200px;
  }
  .course-item .lesson-list li:hover{
      /*background-image: url("/static/image/play-icon-yellow.svg");*/
      color: #ffc210;
  }
  .course-item .lesson-list li .free{
      width: 34px;
      height: 20px;
      color: #fd7b4d;
      vertical-align: super;
      margin-left: 10px;
      border: 1px solid #fd7b4d;
      border-radius: 2px;
      text-align: center;
      font-size: 13px;
      white-space: nowrap;
  }
  .course-item .lesson-list li:hover .free{
      color: #ffc210;
      border-color: #ffc210;
  }
  .course-item .pay-box::after{
    content:"";
    display: block;
    clear: both;
  }
  .course-item .pay-box .discount-type{
    padding: 6px 10px;
    font-size: 16px;
    color: #fff;
    text-align: center;
    margin-right: 8px;
    background: #fa6240;
    border: 1px solid #fa6240;
    border-radius: 10px 0 10px 0;
    float: left;
  }
  .course-item .pay-box .discount-price{
    font-size: 24px;
    color: #fa6240;
    float: left;
  }
  .course-item .pay-box .original-price{
    text-decoration: line-through;
    font-size: 14px;
    color: #9b9b9b;
    margin-left: 10px;
    float: left;
    margin-top: 10px;
  }
  .course-item .pay-box .buy-now{
    width: 120px;
    height: 38px;
    background: transparent;
    color: #fa6240;
    font-size: 16px;
    border: 1px solid #fd7b4d;
    border-radius: 3px;
    transition: all .2s ease-in-out;
    float: right;
    text-align: center;
    line-height: 38px;
  }
  .course-item .pay-box .buy-now:hover{
    color: #fff;
    background: #ffc210;
    border: 1px solid #ffc210;
  }
</style>
